Why would a sugar substitute backfire" Swithers and Davidson wrote that sweet foods provide a "salient orosensory stimulus" that strongly predicts someone is about to take in a lot of calories. Ingestive and digestive reflexes gear up for that intake but when false sweetness isn't followed by lots of calories, the system gets confused. Thus, people may eat more or expend less energy than they otherwise would.
The good news, Swithers says, is that people can still count calories to regulate intake and body weight. However, she sympathizes with the dieter's lament that counting calories requires more conscious effort than consuming low-calorie foods.
Swithers adds that based on the lab's hypothesis, other artificial sweeteners such as aspartame, sucralose and acesulfame K, which also taste sweet but do not predict the delivery of calories, could have similar effects. Finally, although the results are consistent with the idea that humans would show similar effects, human study is required for further demonstration